Circumcision has been an important part of many cultures throughout history, usually for religious purposes. In today's world it is still practiced in some regions for similar reasons or completely different reasons. Unfortunately these are not fully understood or recognized by most.
The difference
The difference between a circumcised and uncircumcised penis is simple. One has skin and the other doesn't. Compare it to a banana peel. Only difference is that an uncircumcised penis can be "peeled" or "unpeeled" at will. A curcumcised penis is peeled forever. Now let's move on to the common misconceptions about circumcision.
It is more hygienic
This one has always been confusing to me. As an uncircumcised male in his mid 20s, I have never quite understood what is so inherently "dirty" about an uncircumcised penis. As previously stated, one has a "peel" of skin over it and the other doesn't. We live in the 21st century which means we have these nice things known as S-H-O-W-E-R-S. It is as simple as folding back this "peel" of skin and running water over it. I have never had any type of bacterial infection or any unpleasant smells down. My penis has always been 100% healthy. I also find that a a penis is significantly more easy to clean and maintain than a vagina regardless if it is circumcised or not. Nearly every female experiences at least one or two vaginal infections during the course of their lives and have to routinely visit gynecologists to make sure they are healthy down there yet you don't see people butchering their labia for "hygienic" purposes.
It looks nicer
I've had many women tell me that they circumcised their sons because "it looks nicer" or "it looks neater." This one has always made me cringe. What if a man had a surgical operation conducted on his daughter's vagina because it "looked nicer." Would that not be creepy to you? Why should a parent care how "nice" their children's genitalia look?
It's normal
Maybe in the US and some isolated parts of Africa but elsewhere, no it's not normal. There is no purpose behind doing it whatsoever. In fact most parts of the world including Europe and Asia, people view it the other way around. The natural penis that you are born with is normal whereas cutting off a sleeve of skin from an infant's penis without their consent is far from normal.
It's your body and your choice
I don't care what anyone says, altering your body permanently should be your own choice whether it be piercings, tattoos, or cutting off hunks of genital flesh. Why does one have to wait until their 18th birthday to get a tattoo yet they can have their genitals butchered within minutes of birth?
It's unnatural
Lastly I'd just like to finish by bluntly saying it's unnatural. Our bodies aren't meant to have flesh removed from down there. There are many things that change in direct response to circumcision. One of these is the sensitivity of the penis. Having no foreskin to sheath the penis results in the desensitization of the glans (head). It will constantly rub and touch against clothing over your lifetime making it far less sensitive than it would be if it had a protective layer of foreskin. This goes back to the previously specified religious purposes. The desensitization was thought to reduce sexual urges thus reducing chances of masturbation or premarital sex. Another notable difference is in the general biology. Both male and female genitalia have microscopic glands known as mucus membranes. These are responsible for the permantly soft and slightly sticky feeling and appearance of genitals. These fluids keep the genitals clean and mositurized. Circumcised men don't have foreskin to protect their penis thus theirs are more likely to have a dry and shriveled appearance. This also has a direct response on sexual intercourse and is why many women experience pain during sexual intercourse. Not only does foreskin produce it's own moisture but it also retains vaginal lubrication during intercourse. A circumcised penis will remove these secretions without retaining any.
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